Cable connector



J. M. CALLER 3,034,088

CABLE CONNECTOR 4 Sheets-Shear?l l May 8, 1962 FiledAJune 26, 1961 May 8, 1962 J. M. CALLER 3,034,088

CABLE CONNECTOR Filed June 26, 1961 l 4 sheets 5heet 2 INVENTOR.` James M. Ca//er Attorney May 8, 1962 J. M. CALLER 3,034,088

CABLE CONNECTOR Filed June 26, 1961 4 Sheets-Sheet 3 Aller.. ey

3,034,088 CABLE CNNECTR James M. Caller, Albuquerque, N. Mex., assignor by mesne assignments, to the United States of America as represented by the United States Atomic Energy Commission Filed .lune 26, 1961, Ser. No. 119,751 6 Claims. (Cl. 339-45) The present invention relates generally to cable connecting means and more particularly to a coaxial cable connector in which the mating parts are forcibly separated from each other when the connector is in an unlocked condition.

In the cable connector field' the electrical connection between two or more conductors is normally attained by placing the connector components together and then in some manner provide a holding or locking relation therebetween for establishing and maintaining an electrical path through the conductors. However, when it is desired to break the electrical path by disconnecting the connector components la serious drawback lis sometimes encountered in that when the locking means is in an unlocked condition, it is still possible to leave the conductorselectrically connected due to the failure ofthe connector mating parts from being completely separated from each other. Therefore, it is an important object of the present invention to provide a connector which forcibly separates the connector mating components when the locking means is in an unlocked position, thus precluding any possibility of leaving the conductors electrically connected.

' Another object is to provide a connector incorporating a rapid and positive connecting and disconnecting bayonettype coupling.

A further object is to provide a new and novel clamping means for securely joining a round coaxial conductor to a connector component.

A still further object is to provide a new and novel clamping means for securely joining -a at coaxial conductor to a connector component.

A still further object is to provide a spline locking arrangement `for rendering the connector resistant to shock Aand viibration.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to. herein will occur to one skilled in the art upon employment of the invention in practice.

Preferred embodiments of the invention lhave been chosen for purposes of illustration and description. The preferred embodiments illustrated are not intended to be exhaustive nor to limit the invention to the precise forms atent C) l ice FIG. 7 is a longitudinal sectional view showing a modified form of the plug portion which is adapted to contain a dat coaxial cable.

With reference to the embodiment illustrated in FIGS. 1-6, the connector of the present invention, generally indicatedat 10', comprises a receptacle por-tion 11, which may be normally fastened to a panelor the like, and a one end thereof a centrally located recess 15 surroundedby lan yannular recess 16. A conductor 17, which may correspond to the inner conductor of a coaxial cable,'ex

tends through the bushing 14 and is secured thereto in any suitable manner. The conductor 17 terminates at one end adjacent rto the base of recess 15 in the form of a socket or receptacle 18 and at the other end with an electrical contact 19. Anannular terminal member 20 may be securely fastened to contact 19 by crimping a Ithin portion 21 of the terminal member 20 into a small disclosed. They are chosen and described in order to best explain the principles of the invention and their application in practical use to thereby enable others skilled in the art to best utilize the invention in various embodiments and modifications as are best adapted to the particular use contemplated.

In the accompanying drawings:

FIG. l -is a longitudinal sectional view of one form of the assembled connector;

FIG. 2 is a longitudinal sectional view of the connector receptacle portion;

FIG. 3 is a longitudinal sectional view of the connector plug portion containing Ithe round coaxial conductor;

FIG. 4 is ka transverse sectional view along lines 4--4 inFlG. 1 illustrating the spline coupling section;

FIG. 5 is a plan view illustrating the bayonet cou- Plng;

FIG. 6 is a transverse sectional view Ialong lines 6-6 of FIG. l; and

recess 22 about the periphery of conductor 17. A raised exterior shoulder 23 maybe placed intermediate the ends ofthe bushing 14 for accommodating an encircling metal housing 24. i l The metal housing 24 encircles a major length of the bushing V14 Aand may correspond generally to the'outer conductor of a coaxial cable.` The housing 24 may be secured to the bushing 14 by providing the housingv 24 with a recessed'portion 25 having an end wall abutting against one side of the bushing shoulder 23. A relatively thin housing portion 26, which may be provided with screw threads 27 on the outer surface thereof forattaching the receptacle portion 11 to a panel or the like, extends endwise a distance slightly greater than the width of the bushing shoulder 23 and m-ay be peened against the side 28 of shoulder 23 to effect a secure attachment of the housing 24 to the bushing 14. It may be desirable to provide a small slant to bushing side 28 to afford a better `seating surface for the peened housing portion 26.` While the connecton between the housing and bushing is v preferably established by ra peening operation, it will be obvious to those skilled in the art when practicing the invention thatV other means of attaching the housing to the bushing will be readily available, such as, for example, a snlap ring or the like placed between the side 2S of the shoulder and a groove in the housing portion 26. A ilange 30 may be placed on the housing 24 adjacent the housing portion 26 for preventing said portion from passing through the opening in the panel and for the purpose of establishing 4a tight connection between the threaded housing'portion 27 and a nut means (not shown), on the opposite side of the panel. Adjacent flange 30, as

best shown in FIG. 4, is a smaller second flange 33 having on its surface a plurality of grooves 34 separated by a pairl of lands 35, which function to lock the plug portion 12 to the receptacle portion 11 as will be described in detail below. While the groove and land relation above described attains a highly desirable locking arrangement, it will be obvious that many other groove designs with or without separating lands may be used. A small lip 36'may also be provided onY each of the lands 35 to accomplish a hold-olf operation which will be described below. Between the second ange 33 and the other end of the housing 24 is a longitudinally extending recessed housing surface 37 which may contain-on the outer surface thereof at least two pins 38 circumferentially spaced 180 apart from each other for establishing a bayonet-type' connection with the plug portion 12. While two pins 38l tionlz adapted for Vuse with the round coaxial cable com prises -a hollow insulating bushing 40 made of any suitable. insulating material, which has at one end thereof a Y slanted end wall 41 and at the other end a centrally recessedY longitudinally extendingannular portion 42 whichis adapted-toV slide into the annular recess 16 of bushing 14 when the plug portion 12 is joined to the receptacle will beV obvious that any leaving sufficient lengthrfor completely covering the thin spring section 56.

A metal sleeve 57 having an inwardly projecting end wall 58 and an inwardly disposed indenture 60 is adapted to slide over the threaded bushing 49 with the indenture 6i? mating with a longitudinally extending slot 61 in the surface ofthe threaded bushing 49, thus preventing thebushing 49 from rotating with respect to the sleeve 57.

portion 11. The annular portion 42 cooperates with recess Y 16 to provide a highly advantageous feature in that when the connector 10V is coupling a high voltage circuit the effective llengtliof the creepage path between the respective .conductors-is greatly increased by the path formed by portion 42 and the Vrecess 16.v The inner conductor .44of the roundcoaxial cable 13N is separated from the outer conductor 46 and the cable insulating jacket 47 by a dielectric spacer 45.' The inner conductor 44 is preferably slightly longer than the dielectric spacer 45 and may be j fastened fby soldering or the like to a pin or plug member 48 which is adapted tomate .with the.socket 18 of therec'eptacle portion 11.v Y v Y VAn annular insulating bushingY 49 having an outwardly tapered end wall 50 which may be substantially parallel suitable binding `means is adapted to be screwed or .otherwise positioned overthecable jacket 47 so as to cause the threads to Vbite into the jacket 47 vand hold thebushing 49 in a desired 'location onthe coaxial cable 13. v`The inner conductor 44,"the dielectric spacer y45 and the plug member 48 are then passed substantially through the hollow bushing 40 to a-point where a shoulder'52 to attain the desired binding effect upon outer conductor 46 .between the walls 41 'and 51.v The cable jacket 47 on the 4coaxial cable 13 maybe terminated near the base ofthe slanted end wall 41 before the bushing 4t) is placed over theinner'conductor 44 or just prior to the adjustment of the threaded bushing 49; Y

To providethe means for forciblyseparating the plug portion 12; 'from the receptacle portion .11 a relatively stii helically Wound compression spring 54 which may be of any suitable type, such as, for example, a spring machined from a soft metal tube by rstA cutting a narrow helical groove through the tube Wall .and extending Vsuch groove,

to points adjacent the ends of the spring so as to leave the spring boxed in at'each end, and then spreading the groove to the desired spring length and finally harden- Ying the spring metal in :this desired shape, is positioned around a substantial'length of the bushing 40 and abuts a raised shoulder V55 Aadjacent the bushing end wall 41. The spring 54 has a relatively thin section 56 adjacent the shoulder 55 so as to be substantially level with the latter.

It may be necessaryto adjustably move the The sleeve 57 includes a projection 64 which is of sutlicient diameter so as to lit over the outer conductor 46 and thin spring section 56 and may be secured in such position by attaching Ythe thin spring section 56 to the sleeve projection 64 bysoldering or the like Vwhich also securely fastens andelectrically couples the outer conductor 46 to the spring section 56. It may be desirable to provide the sleeve projection 64 with small apertures 66 so as to provide a better soldering joint. A

A metal housing 68 which is adapted to encircle the entire plug portion 1,2 and may correspond generally to a supplemental electrical path for the outer conductor of a coaxial cable is provided with an inwardly t disposed llange 69 near one end thereof and may be moved into v positioniover the sleeve 57,-and spring 54 to where the to the slanted end wallv41 of bushing 40 and which may vbe provided with la threaded inner surface 51 or any other f having a generally frusto-conical shape which may be sei one side of housing ange 69 abuts the sleeveend wall 58. The inwardly projecting ange 69 contains a plurality of evenly spaced apertures 'i0 therethrough which are adapted to house a pair of members 71 axially extending from the end wall 58 for preventing rotary movement of the housing 68 with respect to the sleeve 57. Once the housing 68 is movedinto place over the spring 54 and sleeve 57 itis held in position by spring lock 72 ,r cured in a slot 73'of the housing 68 by a pressed t or This spring, which may 'provide the main electrical path between the outer lconductor 46 and the housing 24 of the receptacle portion 11, is'axially compressed as the plug portion V12andthe receptacle portion^11V are joined so as to forcibly eject ther'plug portion 12 from vthe receptacle portion 11 whensuch portions lare in l'an unlocked conditionY as will be describedirifdetail below.Y After the spring 54 ispositioned on the bushing V40 or atY any other of quadrings or the like and are placed inside the housingf 68 adjacent the outer side of the housing ange 69 with the spacer 76 positioned thereagainst. The packings 77V and 78 are held within the interior of housing by an end wall 79 which may be secured to the housing by a pressed fit, soldering, peening a portion of housing 68 over the end wall 79 orin any other suitable manner. By using koversizepackings 77 and 78 an adequate seal may be attained due to the packingsV bearing into the surface of theA cable jacket 47.

The endof the housingV 63 surrounding the plug member 48 is provided with an elongated recess Sli between two annular shoulders 81 and S2. A compression spring 83fof. greater diameter than the forwardly disposedshoulder S1 is placed within the recss Y84) to perform a connecting function to be described. The shoulder 81, as best viewed in FIG. 6, maybe provided with a plurality of grooves 85 arranged on the periphery thereof and spaced apart from each other by lands 86. A movable sleeve 87 is` placed over .the housing 63 and encircles the shoulders 81 and 82. The forward portion of the sleeve 87 or the portion nearest the shoulder 81 is smaller in diameter than the spring 83, thus providing a surface or lip 88 which abuts the spring 83 and prevents the sleeve 87 from moving freely rearwardly over the shoulders. The rear portion of the sleeve 8'7 is slightly greater in diameter Athan shoulder'SZ and may be provided Vwith an Vannular recess 89, so that when the sleeve lip 88 abuts the spring 83 a locking snap ring 96 or the like may be placed, in the recess 89 so as to bear against the rearr'of shoulder 82 and thusprovide a suitable sleeve retaining arrangement which will allow the sleeve 87 to move ,rearwardly against the bias Vof the spring S3. The inner surface of the forward portion of the sleeve 87v so as toV engage a shoulcontainsa plurality of splines 91 (FiG. 6) which are adapted to engage the grooves S5 in shoulder 81 and prevent free rotary movement of the sleeve 87 when the latter is attached to the housing 63 as above described. The splined inner surface of the sleeve S7` extends forwardly ofv the shoulder 81 and is arranged to engage the grooves 34 (FIG. 4) in flange 33 of the receptacle portion 11 when the mating operation is performed as will be described below.

The forward portion of the housing 68 is annular 1n form and is radially spaced from the spring 54, thus forming an annular recess for receiving the housing surface 37. The inner diameter of this forward portion is slightly greater than the outer diameter of the recessed housing surface 37 of the receptacle portion 11. An annular slot 92 is provided on the inner surface of the housing 68 adacent the end of the forward portion and is of sufficient width and depth so as to house the pins 38 of the receptacle portion when the connector is assembled. pair of axially extending grooves 93, as best shown 1n FIG. S, are circumferentially spaced 180 apart from each other and are cut into the inner surface of the housing 63 'for providing communication for the pins 3S between the forward end of the housing 63 and the slot 92. lt may also be desirable to provide a pair of slightly concave surfaces 94 in the forwardly disposed wall of the slot 92 so as to provide a better seating surface for the pins 38 in event of operating conditions where shock and/ or vibrations are present.

A resilient Washer or seal 95 may be placed in a second annular slot 96 on the inner surface of housing 68 to 'provide a seal between the plug portion 12 and the receptacle portion 11 when they are joined.

With reference to FIG. 7, a modified form of the plug portion 12 is illustrated and differs from the round coaxial cable carrying plug portion 12 by its particular adaptation to a dat coaxial cable. Many parts of the modified plug portion are similar in both structure and function to variousv parts in the plug portion 12 and will 'thus be identifiedv by the same reference numerals.

The modified plug portion generally indicated at 100 comprises an annular insulating bushing 101 having a through-going rectangularly shaped passage 103 therein and an outwardly disposed shoulder d adjacent one end thereof. A flat cable 165, which may be of any desired design, such as, for example, a fiat foil inner conductor 107 positioned between a pair of dat foil outer conductors 108 with each being separated from the inner conductor 107 by a layer of insulating material 109 and with all three conductors being encased in a rectangularly shaped outer insulating jacket 110, may have the conductors separated from each other a sufficient length, ie., peeled Yapart so as to leave the inner conductor 107 and the layers of insulating material 109 separate from the outer conductors 108 while terminating the outer insulating jacket 110 adjacent the point of conductor separation, so that the inner conductor 107 and the insulating material 109 may extend through the passage 103 of the -insulating bushing 101. The inner conductor 107 which may extend beyond bushing 101 a slight distance is adapted to be fastened to a pin or plug shaped member 111 in any suitable mamier, such as, soldering or the like.

`An annular insulating member 113 which may extend endwise a length substntially greater than the insulating bushing 101, is adapted to completely encircle bushing 101 and be rigidly attached thereto in any suitable manner, such as, for example, by providing threads 114 on the surface of shoulder 11M which mate with threads 115 on the inner surface of member 113. An inwardly disposed shoulder 117 on the insulating member 113 is adapted to abut a shoulder 118 on the plug member 111 and rigidly secure the plug member 111 in its desired Lposition when the member 113 is joined to bushing 101. -An annular extension 42 of the member 113 forms a .central recess 119 "and is adaptd tov slide into the annular recess 16 of bushing 14 when the plug portion 100 is joined to the receptacle portion 11.

A compression spring 120, which is adapted to perform its functions in the same manner as compression spring 54 (FIG. 3), may be provided with an annular shoulder 121 near the inner end thereof for rigidly .securing the spring in the plug portion 100 as will be described below. The spring 120 may also have a recessed inner portion 122 which is adapted to abut a raised shoulder 12d on the member 113 thus preventing the spring 120 from endwise movement in one direction with respect to the insulating member 113.

Each outer conductor 108 is adapted to be attached to the spring I1213 by placing each foil vconductor 103 on a portion of a relatively thin annular spring section 125 and securing such conductors in place by encircling the conductors with a sleeve 126 having a plurality of perforations 127 therein and then iilling such perforations with solder or any other suitable bonding agent to bind the conductors 108 to the spring 120.

An outer shell or housing 129 corresponding generally to the housing 68 is slipped over the spring 120 to Where an inwardly disposed shoulder 130 on the shell 129 abuts the spring shoulder 121. The shell 129 may be held in this abutting relationship with the spring 120 by providing a threaded sleeve 131 which is adapted to be inserted inside of the shell 129 `and mate with an internally threaded surface 133 of the shell, thus causing the sleeve 131 to bear against the other side of shoulder 121 to hold the spring 120 rigidly within the shell 129.

A soft rubber cable gromrnet 135 having a beveled forward edge 136 and a rearwardly disposed shoulder 137 is adapted to surround the flat cable and be positioned within the shell 129 to Where the gronLnet 135 abuts the sleeve 131 and the beveled edge 136 abuts a converging surface 138 on the inner surface of the shell 129. The rubber grommet 135 may be held in its abutting relationship by an externally threaded annular ring 139 which may be inserted inside the shell 129 and mate with an internally threaded portion 140 of the shell 129. A washer or the like 141 may be positioned between the ring 139 and the rubber grommet 135 to substantially eliminate the -frictional forces that would occur therebetween. It may also bel-desirable to bond the rubber grommet 135 to the flat cable by a suitable cement to effect a seal and to help hold the flat cable in its desired position.

The components in `the forward end of the plug portion 100 designated by numerals '42, 80, 81, 82, 83, 87, S3,

39, 90, 91, 92, 94 95 and 96 are similar in design and function to the components of plug portion 12 having llike designations in FIGS. l and 3'-6.

Operation sary to pass the annular forward portion of the housing 68 over the recessed housing surface `37 of the receptacle portion 11 and align the axially extending grooves 93 with the pins 38. The plug portion 12 is then moved by gripping the housing 63, which may have a knurled surface thus mating the pins 38 with the grooves 93 and the inner conduc-tor plug 48 with the inner conductor socket 18. As :such movement takes place, the end of the recessed housing surface 37, which may be slightly tapered to ease alignment, abuts the forward end of compression spring 5d, compressing the latter. The splines 91 -on the sleeve 87 may at this point be v45" out -of alignment with .the grooves 34 on ange '33., thus the splines 91 on sleeve S7 merelyvabut the hold-oli lip 36 causingthe sleeve S7 Vto be moved rearwardly against the bias of spring 83. When substantially the limit of pin 3S travel in the grooves 93 is attained, the entire plug portion 12 is rotated 45 in either direction, moving-the pins circumferentially in the annular slot 92. Simultaneously with the completion Vof such rotation and Awith the alignment of splines 91 with the grooves 34, the spiing'biased'sleeve 87 snaps forward to mate the splines 9i with the grooves 34. The resilient gasket 95 engages the tapered portion of the recessed housing surface 37 Vand is sufficiently deformed so as to provide a seal between the mating parts. While the splines 91 are disclosed as normally being 45 out of alignment with the grooves 34, ,it will be obvious to others skilled in the art to use any desired degree of spline and groove misalignment; in fact, by'merely preventing the sleeve 87 from snapping forwardly to engage the splines 91 with the grooves 34 when the 45 of rotation is attained, it is possible to place the pins 3S in any desired location within the slotV 92.

When the' mating parts of the connector are thus assembled, it will be seen that the plug portion 12 is securely locked to the receptacle portion l1, since the pins 38 within the'annular slot 92 prevent relative longitudinal movement of either mating part. Furthermore, *the pins 38 are retained in place within the slot 92 due to the engagement of splines 91 with grooves 34, thus preventing rotational movement of either mating part which could move Vthe pins 38'into alignment with the grooves 93 causing disengagement. The spring 54, due'to its contact with the housing 24 and its connection to theouter'conductor 46 acts Vto hold the pins 33 against the concave surface 94 and also serves as the main current path for the outer conductor of the coaxial cable 13 while the outer portion ofthe connector serves as the secondary 'current flow path. To 'separate the mating parts Vfor terminating the electrical path through the connector the sleeve 87, which may have a lmurled surface Vfor providing an adequate gripping surface, is moved rearwardly against the bias of spring 83 until the splines 91 aremoved entirely out of the grooves 34. The plug portion 12 is then rotated in either direction until the pins 3S are aligned with the Vgrooves 93. The compression spring 54, which is in a loaded or compressed condition, instantlyimposesia reelling force between the mating parts to rapidly sepa- Y `rate the plug portion 12 from the receptacle portion 11,

l j j 8 Y A that all matter herein is to be interpreted as illustrative and not in a limiting sense. 'Y Irclaim: I i 1 Y 1. A device of the character described comprising in combination -a pair of mating portions, one of said por` tions having an insulating member with a centrally located throughgoing conductor therein and an annular externally disposed shoulder means intermediate the ends thereof, a metal shell surrounding a portion of said insulating member and secured to said shoulder means, annular flange Ameans projecting radially from the surface of said shell and having a groove therein, pin means projecting from Y the surface of said shell intermediate said ange and one end of said shell, an annular longitudinally extending recess within said insulating member and communicating with one Vend of'said member adjacent said one end of the shell, the other of said mating portions having an insulating means including an annular' longitudinally extending portion adapted to engagersaid recess and a centrally located throughgoing conductor arranged to mate with said first mentioned conductor providing a rst current path, a helical compression spring encircling a portion of said insulating means and adapted to abut an outwardly extending shoulder thereon, one end of said compression spring arranged to engage said one end of the shell and resist the mating of said portions, a second conductor in the other of said` portions being coaxially disposed with respect to the second mentioned conductor and secured to the other end of said compression spring providing a Vsecond current path through saidV spring and'said shell, another shell surrounding said spring and insulating means and having a pair of outwardly disposed and longitudinally spaced shoulders thereon one of which contains a groove in the outer surface thereof, means for securing said other shell to spring, bias means disposed between 'said shoulders and having a diameter greater than the diameter of Said grooved shoulder, sleeve means adapted to surround said shoulders with an inwardly disposed lip abutting one end of said biaslmeans and having an inner surface with a spline projecting therefrom for engaging YVthe groove in the groovedV shoulder, said inner surface having a longitudinal length substantially greater than sleeve 87 attains a highly desirable feature in that after the pins 38 are suiiiciently within the grooves 93 the plug portion 12 may be rotatednin either direction to eiect engagement of the splines 91L with the grooves 34. The excess number of grooves Y34 also cooperate with the concave Wall94 of the slot 92 to provide a novel arrangement especially when the connector is subjeged to shock loads. If the connector 10 receivesY a severe enough shock in a given direction it is highly possible for the sleeve 87 to slide rearwardly and cause disengagement of the splines 91 with the grooves 34; however, due to the concave Wall 94 the pins 38 will not move towards the grooves 93 but will tend to seek the innermost point of the concave surface and as the shock 4force is lrelieved the sleeve 87 snaps back, again mating the splines 9i with the grooves 34. Also by varying the number and arrangement of the pins 38 and grooves 93 on each connector where several connectors are to be used in close relationship to each other suitably sets ,forth a means of preventing crossplugging.

As various changes may -be lmade in the form, construction and arrangement of the parts herein without departing said grooved shoulder so as to enable said spline to engage the groove in said flange, said other shell and said insulating Vmeans forming anrannular recess for admittance of said first mentioned shell and pin means, said other'shell having disposed on the inner surface and adjacent one end thereof a circumferentially extending groove with a longitudinally extending slot communicating said one end thereby permitting said pin means to enter said circumfer-V entially extending groove through said slot and subsequent rotation of said other portion moves said pin means circumferentially Within said shell groove away from said slot and aligns the groove in said flange with the spline in said sleeve causing said bias means to urge said spline into said flange groove.

2. The device claimed in claim l wherein a plurality of grooves separated by lands are disposed on the surface of said ilange and said grooved shoulder, and with said splined sleeve having a lesser number of splines cooperating with said plurality of grooves.

3. The device of claim 1 wherein a locking ring is positioned between one side of the other shoulder on said other shell and an annular vgroove on the innerY surface of said sleeve thereby preventing said sleeve from excessive endwise movement in onedirection` 4. The device-claimed in claim 1 wherein said ooaxially disposed conductor is annular in form and separated from the second mentioned conductor by a cylinder of dielectric material, said annular conductor is secured to said spring Yby a sleeve means having an inwardly extending `endwall with a pair Vof laterally extending projections thereon and an indenture in a surface thereof and m insulating means having a recess in an outer surface adapted to mate withsaid indenture and arranged to abut said sleeve endwall thereby holding said annular conductor against an inclined end surface of said first mentioned insulating means, said other shell has an inwardly disposed and perforated ange adapted to receive said lateral projections, and sealing means is provided between said perforated ange and the other end of said other shell.

5. The device claimed in claim 1 wherein said coaxially disposed cable comprises a pair of ilat foil-like conductors normally separated from `the second mentioned conductor by a pairA of flat insulating members, each of said foillike conductors is secured to said spring by a perforated sleeve means adapted to hold said foil-like conductors against a surface of the other end of said spring by bonding material Within said perforations, said means for securing the other shell to said spring comprises an annular radially extending shoulder 0n said spring wit-h one side surface thereof adapted to abut a recess in said other shell with a threaded annular sleeve means engaging a threaded inner surface on said other shell adapted to abut the other side surface of said spring shoulder, resilient means surrounds said flat cable and is positioned within said other shell against one end of said threaded sleeve and abuts a converging inner surface on said other shell, and means wherein means is adapted to hold said resilient means within said other shell.

6. The device claimed in claim-1 wherein said circumferentially extending groove is provided with a concave sidewall forming a seating surface for said pin means.

References Cited in the iile of this patent UNITED STATES PATENTS 1,001,994 Schneider Aug. 29, 1911 2,409,650 Wiggins Oct. 22, 1946 2,561,677 Souriau July 2A, 1951 2,728,895 Quackenbush et al Dec. 27, 1955 2,757,351 Klostermann July 31, 1956 2,785,385 Figueira Mar. 12, 1957 

